Re: Composing Hebrew diacriticals

[Kenichi Handa <handa@m17n.org>]

In article <83mxwlw2c0.fsf@gnu.org>, Eli Zaretskii <eliz@gnu.org> writes:

> AFAICS, Hebrew diacriticals are not currently composed with
> consonants, even in the pre-bidi display.  Is that true?

Yes.

> If it's true, what will it take to construct the appropriate
> composition rules for the diacriticals?

This will be ok.

(set-char-table-range 
 composition-function-table '(#x591 . #x5F4)
 '(["[\u0591-\u05F4]+" 0 font-shape-gstring]))

On Windows, I expect uniscribe already has capability to
handle that.

On GNU/Linux, unfortunately, m17n-db packages of various
distribution is not yet updated.  So, you have to install a
few database files manually.  I'll prepare those files soon
so that GNU/Linux users can test hebrew composition easily.

> I tried to read composite.el and some of the files in lisp/language
> that appear to use its facilities, but quickly got lost, probably
> because I know to little about this matter.  The ELisp manual also
> doesn't document these facilities, unfortunately.

Sorry for my laziness.  For composition, there are many
stakeholders and I'm still wondering to what degree to
document.  For instance, you have to understand what
OpenType font can do and what it can't do.  The former part
can be delegated to font-shape-gstring, but the latter part
must be implemented by lisp.  The characteristics of
terminal (graphical or charater) must also be concerned.
I'll provide a proper internal document (i.e. for Emacs
developpers) in haste.

---
Kenichi Handa
handa@m17n.org